Electrical disconnection systems include one or more disconnection switches. A disconnection switch (e.g., a relay) selectively connects or disconnects electrical devices to/from one another. For instance, a disconnection switch selectively connects or disconnects a battery and a load. Disconnection systems are used in an assortment of vehicles including vehicles powered by an internal combustion engine and having a stop-start system, vehicles having multiple batteries, and hybrid vehicles. Depending on requirements, the disconnection systems may employ a normally closed (“NC”) disconnection switch, a normally opened (“NO”) disconnection switch, or both of a NC disconnection switch and a NO disconnection switch. In some cases, measurement of disconnection switch voltage and switch current is to be taken.